Metallic particulate

Abstract

A method of providing a particulate suitable for use in, for example, coating compositions, such as paints. The described method comprises depositing a metal on a substrate by, for example, electroless or vapor deposition methods. The metal deposit is then removed from substrate to provide a plurality of distinct metal platelets suitable for combination with a carrier and use in a coating composition.

What is claimed is: 
     
       1. A method comprising providing a substrate with a coating on at least a portion of the substrate, the coating consisting essentially of an about 200 to about 600 angstrom thick vapor deposited metal layer, dissolving the substrate to separate at least a portion of the coating from the substrate to provide a plurality of generally separate irregularly shaped metal platelets with a largest dimension up to about 5000 microns, and introducing the metal platelets into a carrier suitable for use in a coating composition. 
     
     
       2. The method of claim 1 wherein the metal coating is aluminum. 
     
     
       3. The method of claim 2, including removing substantially all of the substrate material from the platelets before introducing the platelets into a carrier. 
     
     
       4. A composition comprising a carrier suitable for use in a coating composition and metallic particulate formed by providing a substrate with a coating on at least a portion of the substrate, the coating consisting essentially of an about 200 to about 600 angstrom thick vapor deposited metal layer, dissolving the substrate to separate at least a portion of the coating from the substrate to provide a plurality of generally separate irregularly shaped metal platelets with a largest dimension up to about 5000 microns. 
     
     
       5. A composition comprising a carrier for use in a coating composition and metallic particulate formed by providing a substrate with a vapor deposited coating on at least a portion of the substrate, the coating consisting essentially of an about 200 to about 600 angstrom thick aluminum layer, separating at least a portion of the coating from the substrate by dissolving the substrate to provide a plurality of generally separate irregularly shaped aluminum platelets with a largest dimension up to about 5000 microns. 
     
     
       6. The composition of claim 5 containing up to about 10 weight percent of aluminum flakes with thicknesses of from about 200 to about 600 angstroms. 
     
     
       7. The composition of claim 6 containing up to about 5 weight percent aluminum flake. 
     
     
       8. the composition of claim 6 containing from about 1/4 to about 3/4 weight percent aluminum flake. 
     
     
       9. the composition of claim 8 including a binder. 
     
     
       10. A coating containing the composition of claim 4. 
     
     
       11. A coating containing the composition of claim 6. 
     
     
       12. A coating with a mirror-like secondary surface consisting essentially of a color pigment free mixture of the composition of claim 8 and a binder. 
     
     
       13. The coating of claim 12 wherein the aluminum flakes have an average largest dimension within the range of from about 100 to about 200 microns. 
     
     
       14. The coating of claim 13 containing aluminum flakes previously cleaned to remove substantially all of the original substrate material from the composition. 
     
     
       15. The composition of claim 4 wherein the metal is selected from the group consisting of Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, Cd, Ag, Pd, Rh, Ru, Mo, Nb, Zr, Y, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, and Pb. 
     
     
       16. The composition of claim 4 wherein the metal is selected from the group consisting of Mg, Al, Cu, Au, and Ag. 
     
     
       17. A light bulb with an exterior surface thereof coated with a composition consisting essentially of the composition of claim 16 and a binder, the coating having a reflective surface in contact with the light bulb. 
     
     
       18. A light bulb with an exterior surface thereof coated with a composition consisting essentially of the composition of claim 15 and a binder, the coating having a reflective surface in contact with the light bulb. 
     
     
       19. A light bulb with an exterior surface thereof coated with a composition consisting essentially of the composition of claim 5 and a binder, the coating having a reflective surface in contact with the light bulb. 
     
     
       20. A light bulb with an exterior surface thereof coated with a composition consisting essentially of a color pigment free mixture of the composition of claim 5 and a binder, the coating having a mirror-like surface in contact with the light bulb. 
     
     
       21. A light bulb with a surface thereof coated with a composition consisting essentially of a color pigment free mixture of the composition of claim 8 and a binder, the coating having a mirror-like surface in contact with the light bulb.